19th August 2010: The question, "How fast do cats breed?" is a bit of a news story. I refer to Christie Keith's excellent story, Damn lies and cat statistics in the San Francisco Chronicle of the 18th August 2010. For some time a surprising statistic has been bandied about the internet (as frequently happens) that a single unspayed female domestic cat if left to breed in an unrestricted manner will lead to 420,000 offspring in 5 years. For the sake of accuracy Christie Keith says that the statistic states, "The offspring of a single unspayed cat will, within five years, add up to 420,000 cats."

You can see right away how things get changed when passed along the internet. Franny mentions a period of seven years and Christie refers to five years - no criticism intended.

Both authors rightly say that the figure is incorrect - dramatically so. Christie comes up with a figure of "98 and a high of 5,000 cats in seven years". While Franny says that a projection of 100 to 400 cats at the end of seven years is more accurate.

The stark differences are due to factoring in realistic survival rates as opposed to the perfect breeding scenario. If the survival rate of offspring is 25% rather then 80% then the figure tumbles to the much lower and more realistic numbers.

The sad thing about this story is that authoritative websites and organizations have used the incorrect figure to the detriment of the cat. It encouraged nasty people to brutally shoot the feral cat for pleasure and bird conservationists to demand a more vigorous extermination or control of feral cats. It also supported the skeptics of TNR programs as proof of failure.

Interestingly, it seems that the figure of 420,000 was exaggerated even when calculated on a theoretical basis. Dr Desmond Morris in his excellent book Catwatching published in 1986 addresses the issue of how fast do cats breed.

Dr Morris says that the domestic cat "may produce an average of four to five kittens in each of their annual three litters." He goes on to say that if we start with a single breeding pair of domestic cats, allow for fourteen kittens per year, the total after five years based on simple mathematics is 65,536. From that theoretical figure there has to be deductions for less than 100% survival rates, that males and females are not born in equal numbers and that cats don't all start breeding when a year old (in fact female cats start breeding at a younger age which would push the figure up).

It would seem that the major reducing factor is low survival rates of feral cats and kittens. Other factors include: he suggests that more than 90% of male domestic cats are neutered. There are also the TNR programs that have a reducing impact. And people who aren't formal cat breeders who allow their cats to breed may have kittens killed by their vet to reduce litter sizes (I am not sure about this last point).

In short there are many mitigating factors that reduce the numbers of offspring. The greatest problem that has been highlighted from this story is that we must be cautious in using the internet when searching for so called "facts". Assumptions should not be made even when the source seems fine. Sources should always be noted and often the best source is a book or research study. A study will at least quote true facts and opinion and divide the two.

I endeavor at all times to adhere to what I advise.

Note: the European wildcat has a single litter each year and an average of two to four kittens per litter (source: Catwatching)

Comments for How Fast Do Cats Breed?

If the cat is not dying BEFORE they can breed, then their longevity means NOTHING to breeding rates. I can't believe you cat-advocates will blind yourselves this much with nonsense just to try to justify your own ignorance and stupidity.

Dec 14, 2010Rating

How fast do cats breed? Theory and Practical cases.by: Anonymous

In theory on "Paper" its very easy to project astronomical figures of a pair of breeding cats ,numerical statistics beyond human imagination. In practise, its totally different as few kittens survive in the wild, besides, most feral cats have a short life-span compared tp domesticated pet cats receiving veterinary care. Strangely, some pet "tom cats" prove duds at stud as is the case with my handsome tradional persian tom-cat matata, now aged 20 months. I tried breeding "Matata" to his dam "matahari', an inbreeding effort to improve the breed but have been totally unsuccessful. Either matata is afraid of his dam matahari or he is too humanised and hence lacking the natural temperament of the average virile breeding tom-cat.Manny professional cat breeders must have faced the same problem as i do with the pair of "Matahari/Matata"."Breeding' even under ideal conditions is never a perfect science, a harsh truth which i personally experienced with my cats matata and matahari.According to "Paper statistics" matata and matahari would have parented dozens of kittens to date(15-12-2010),totally untrue, proving the fact that all statistics are never accurate.

Aug 22, 2010Rating

To Oakleyby: Michael

My pleasure in using your photo. I always credit Flickr photographers and link to their Flickr page often. Flickr has recently added a facility whereby you can link direct to the photo and when I do that I don't give a credit because the photo links back to the Flickr website and the photographer's photostream. I believe I don't have to provide a credit under these circumstances but am happy to do so.

Aug 20, 2010Rating

Good Articleby: Gail (Boston, MA USA)

Thanks Michael for addressing the erroneous information out there about breeding cats. It's easy to think that everything read on the internet is factual, when that's the furthest from the truth.

Oakley, great photo. What's the chance of your mom trapping the pair of cats under the floor and getting them neutered? If there's a TNR program in your area, that would be ideal.

Aug 19, 2010Rating

Thanks for crediting my photo!by: oakley

Most people would just steal the image and never credit you for anything. So, thank you! 🙂

And great article about feral cats. My in-laws had tons of them under the house. One fall, nature took care of that. Either bears, foxes, or wolves in the mountain left behind perhaps a pair. The house smells of whatever they've got going on below. But now it's just down to 2 adults and 6 kittens. Mom keeps feeding them so they never leave!